How To Calculate Difference In Dates In Excel 2016

Calculate the difference between two dates in Excel 2016 with precision. Get results in days, months, or years with our interactive tool.

Comprehensive Guide: How to Calculate Date Differences in Excel 2016

Calculating the difference between dates is one of the most common tasks in Excel 2016, whether you’re tracking project timelines, calculating employee tenure, or analyzing financial periods. This comprehensive guide will walk you through all the methods available in Excel 2016 to calculate date differences accurately.

Understanding Excel’s Date System

Before diving into calculations, it’s crucial to understand how Excel stores dates:

• Excel stores dates as sequential serial numbers starting from January 1, 1900 (date serial number 1)
• January 1, 2000 is stored as 36526 because it’s 36,525 days after January 1, 1900
• Time is stored as fractional portions of a day (0.5 = 12:00 PM)
• Excel for Windows uses the 1900 date system, while Excel for Mac uses the 1904 date system by default

Basic Date Difference Calculation

The simplest way to calculate the difference between two dates is to subtract them:

1. Enter your start date in cell A1 (e.g., 1/15/2020)
2. Enter your end date in cell B1 (e.g., 6/20/2023)
3. In cell C1, enter the formula: =B1-A1
4. The result will be the number of days between the two dates

To format the result as a number of days:

1. Right-click the cell with the result
2. Select “Format Cells”
3. Choose “Number” with 0 decimal places

Using the DATEDIF Function

The DATEDIF function is specifically designed for calculating date differences and offers more flexibility:

Syntax: =DATEDIF(start_date, end_date, unit)

Unit Argument	Description	Example Result
“D”	Days between dates	915
“M”	Complete months between dates	39
“Y”	Complete years between dates	3
“YM”	Months between dates after complete years	4
“YD”	Days between dates after complete years	120
“MD”	Days between dates after complete months	5

Example: =DATEDIF("1/15/2020", "6/20/2023", "Y") & " years, " & DATEDIF("1/15/2020", "6/20/2023", "YM") & " months, " & DATEDIF("1/15/2020", "6/20/2023", "MD") & " days"

This would return: “3 years, 5 months, 5 days”

Using the DAYS Function (Excel 2013 and Later)

The DAYS function provides a simple way to calculate days between dates:

Syntax: =DAYS(end_date, start_date)

Example: =DAYS("6/20/2023", "1/15/2020") returns 1216

Calculating Workdays Only

For business calculations where you need to exclude weekends and holidays:

NETWORKDAYS Function: =NETWORKDAYS(start_date, end_date, [holidays])

Example: =NETWORKDAYS("1/15/2020", "6/20/2023", A2:A10) where A2:A10 contains holiday dates

Function	Purpose	Example	Result
NETWORKDAYS	Days excluding weekends and holidays	=NETWORKDAYS(“1/1/2023″,”1/31/2023”)	22
NETWORKDAYS.INTL	Custom weekend parameters	=NETWORKDAYS.INTL(“1/1/2023″,”1/31/2023”,11)	26 (Sunday only weekend)
WORKDAY	Adds workdays to a date	=WORKDAY(“1/1/2023”,10)	1/17/2023
WORKDAY.INTL	Adds workdays with custom weekends	=WORKDAY.INTL(“1/1/2023”,10,11)	1/13/2023

Calculating Age from Birth Date

To calculate someone’s age from their birth date:

1. Enter birth date in cell A1
2. Use formula: =DATEDIF(A1,TODAY(),"Y") & " years, " & DATEDIF(A1,TODAY(),"YM") & " months, " & DATEDIF(A1,TODAY(),"MD") & " days"

Common Errors and Solutions

Error	Cause	Solution
#VALUE!	Non-date values in formula	Ensure both arguments are valid dates
#NUM!	Start date after end date	Swap the dates or use ABS function
######	Column too narrow for date format	Widen the column or change number format
Incorrect results	Date system difference (1900 vs 1904)	Check Excel options for date system setting

Advanced Techniques

Calculating Exact Years with Decimals:

=YEARFRAC(start_date, end_date, [basis])

The basis argument determines the day count basis (0-4). Basis 1 (actual/actual) is most precise for financial calculations.

Creating a Dynamic Date Difference Calculator:

1. Set up input cells for start and end dates
2. Create dropdown for output units (days, months, years)
3. Use nested IF statements with DATEDIF:

=IF(B1="days", DATEDIF(A2,A3,"D"), IF(B1="months", DATEDIF(A2,A3,"M"), DATEDIF(A2,A3,"Y")))

Visualizing Date Differences with Conditional Formatting:

1. Select your date range
2. Go to Home > Conditional Formatting > New Rule
3. Use “Format only cells that contain”
4. Set rule for dates “less than” or “greater than” specific values
5. Apply color scales to visually represent date differences

Best Practices for Date Calculations

• Always use cell references instead of hardcoding dates in formulas
• Consistently use either the 1900 or 1904 date system throughout a workbook
• Document your date calculation methods for future reference
• Use the TODAY() function for current date to make calculations dynamic
• Consider time zones when working with international dates
• Validate date inputs to prevent errors in calculations

Real-World Applications

Project Management: Track project durations, calculate buffer periods, and monitor deadlines.

Human Resources: Calculate employee tenure, track probation periods, and manage contract renewals.

Finance: Determine loan periods, calculate interest accrual periods, and manage payment schedules.

Manufacturing: Track production cycles, monitor equipment maintenance schedules, and calculate lead times.

Education: Calculate academic terms, track student attendance periods, and manage course durations.

Authoritative Resources

Microsoft Official DATEDIF Function Documentation University of Wisconsin Excel 2016 Comprehensive Guide (PDF) IRS Publication 5093 – Date Calculations for Tax Purposes